Keep in mind our categories are pretty arbitrary. We have stuff like semimetals and so on. All bonding has multiple characteristics outside of extremes, e.g. covalent bonds with dipole character.
Metals are just our name for the broad category of bonding between extremes at conditions we usually find on earth where we live. They are soft squashy bonds that are kinda slutty because they're just sort of average.
Actually within the metals we see some pretty different characteristics, especially with D orbital chemistry stuff but because of inertia we just keep these things all in the same category of metals because shiny squishy was a lot more obvious than fucky wucky complexing when people named them.
Some elements have an unstable electron configuration in their outermost shell, so they want to get rid of those electrons to make the configuration more stable. These elements are defined as metallic, and make up most of the elements.
I'll try my best. I'm not an inorganic chemist, but I did take a class on it once, and I'll try to remember as much from it as I can.
Metals are metallic mainly because they're able to form these vast networks of bonds between many atoms. All the properties that we associate with metals - shiny, conducts electricity and heat, such as that - arise because of how this network of bonds interacts with the environment. For instance, having a network means electrons can go from one side of the network to the other which we observe as being electrically conductive.
In other words, the metallicity of an object is an emergent property that's dependent on how large this network of bonds is and what types of bonds make up the network. As a side note, because we know that the network is the basis of metallicity, we can kind of cheat the system by making networks out of otherwise non-metallic objects, and if we make these networks act similarly to the networks found in metals, we get a non-metal that looks and acts like a metal (what we would then call a semiconductor)
It turns out, the higher energy orbitals that you find on heavier atoms have the tendency to form networks. I don't fully remember why, but I think it has something to do with the fact that when you get so heavy, you have so many orbitals that you can just form a ton of bonds at once (I was surprised to learn that metal atoms can form more than 3 bonds with another metal atom)
So basically the lighter elements tend to be non-metals because they don't have the number of orbitals to form a cohesive network (outside of select cases) and the heavier elements tend to be metals because they have so many orbitals that they kind of have to form networks.
The top poster's wife is correct. Electronegativity is the key.
It seems kind of intuitive, but very difficult to explain.
One definition is that metals can conduct electricity - as in exchanging electrons.
The periodic table is two dimensional. The vertical axis or rows tells how many shells or layers or orbits of electrons an atom has. As we go downwards in the table the exchangeable electrons are positioned further away from the protons, so the electrons are less attached and more likely to be exchanged by close proximity of other atoms.
The horizontal axis is the number of electrons in the outermost orbit. The rightmost ones have full outer orbits and don't have vacancies to exchange electrons, but as we go left, the atoms are more and more short of electrons to fulfil the outermost orbit = electronegativity= missing some electrons.
Combining this shows that the atoms most likely to exchange electrons are in the bottom left corner of the table, which is also the previously mentioned definition of metals.
Someone else pointed out that the actual distribution of atoms is very much not metallic. In the entire universe there is 73% hydrogen, 25% helium and only 2% of everything else including all metals. Even on a planet consisting of "everything else" very much, it's still rare to come by metals, hence their value.
The reason why metals take up so much space on the period table is simply that metals have a lot of different configurations which need to be described because they are different from each other.
Why is it "electronegativity" if they're missing some electrons? Wouldn't that make them electrically positive? I guess it must mean something other than the total electric charge because unless the atom is an ion, that's always 0 (# protons = # electrons)?
Yes, electronegative doesn't mean electrical charge, but simply that it's in the negative of the potential number of electrons in that period. It's a chemical term meant to explain how likely it is to attract the needed electrons, so it increases as it gets closer to the noble elements. I mean, it doesn't express the difference from the ideal number of electrons but the likelyness that it will receive an electron.
The periodic table is a nice overview, but it doesn't really show how stuff works in any logical way.
I think that we have a perception bias towards things that interest us.
Since the elements in the top-right corner (C, O, N, P, S, Si, Fe, Al, Na, ...) are interesting to us, that's what we typically look at. And in that region, things are fairly balanced. It's only in the regions where we don't typically look, where we said "let's just make it all metal so the categorization is done, call it a day, and move on". I think.
It's more the case that in human interactions with the elements, most of them exhibit a metallic phase because we're exposed to the elements on Earth. Out in space elements do weird things. Gaseous clouds of gold, solid metal nitrogen. A lot of elements in the universe are in plasma phase, which isnt common at all on Earth.
Metals are metal on earth because their electronegativity gives them metallic bonds in our atmosphere.
Metals have what're called delocalized electrons, where electrons just kind of wander around a metallic bond between atoms. Metallic bonds involve a very low level of attraction between the nucleus and its electron cloud. Turns out most elements have this, so they do metallic bonding.
It's only when atoms start to get a little wobbly do they exhibit enough electronegativity to perform ionic or covalent bonding, where the molecules donate electrons. Electronegativity increases on the right side of the periodic table when electron valency starts getting lower. And that's the non-metal side.
So the answer is basically that you need more of an electrical charge to exhibit the things we've classified as non-metals. Metals are more chill and generally less reactive.
I should also mention that non-metals have a liquid/solid metallic phase at certain temperatures and pressures. I remember a Chinese study a few years ago claiming to have made metallic nitrogen.
Once you start tacking on lots of electrons, there’s only so many ways to configure them and get stable nuclides with behavior consistent with nonmetals.
I'm not sure what in my answer ticked you off but I wasn't trying to be demeaning or anything. The question boils down to asking why the physical laws are what they are and this is not a question that really has a scientific answer. Perhaps a philosophical or religious answer, but then the answer varies from person to person.
Some people don’t like to read, and/or don’t like truth and facts spoken/written to them. So they take offense to logic and reason, which is what you had in your answer.
It does have a scientific answer, as has been shown in other comments in this thread.
If I ask "why are north Koreans shorter than south Koreans on average?" and someone responds with a wall of text explaining how it's just how it is and that's just life, they might as well have said nothing. "Why" questions usually have an answer, even if you don't know it, leave it to those that do and continue lurking.
I'm not a chemist, but I disagree. You can study elements and discover their properties, such as whether they are metallic or not, but asking why boils down to asking why the physical laws are the way that they are. That is not a question that science can answer.
The physical laws just are the way that they are - unless you believe a god or some other entity defined them with a certain purpose, it does not make much sense to ask why they are like that.
That's blatantly incorrect. The properties of metals is an emergent property that arises from how atoms interact with each other.
Dense network of bonds with a lot of electrons -> higher chance of absorbing incoming light of a particular wavelength -> electron gets excited to the precise energy level of the incoming light due to the dense network of molecular orbitals -> electrons releases the exact amount of energy absorbed when it falls back to ground level -> a photon with equal wavelength to the light that was absorbed is emitted -> we observe that as something being shiny.
There's nothing fundamental about why metals are metallic - inorganic chemists don't just spend their entire day looking at elements and categorizing them as metals or not. Their entire job is figuring out why metals are the way they are. If you want to debate about why quantum mechanics (which is what ultimately causes atoms to interact in a particular way) is the way it is, then sure, we don't know that yet. But then you'd be talking about an entirely different topic than the one that was asked
I think either you're misunderstanding me or you have a different philosophy about the kinds of questions science can answer than I do - which is fine, that's my whole point.
You tried here to provide a kind of explanation, but I personally don't see that as an answer to "why". I mean you say it is because of a dense network of bonds with a lot of electrons. But I could just ask "okay, but why is there this dense network of bonds?".
Then you could give me some additional "explanation" and I could again just ask "okay, but why is it like that?". And I could keep asking why.
My point is that any explanation you give ultimately will boil down to something you observed to just be like that. At some point I'll ask "okay but why" and you'll have to just say "it just is like that" - science cannot give you an answer for "why" something is.
This isn't a matter of just studying the laws of physics further. Even if you studied something more and got another explanation to something more fundamental, I could just ask "okay but why is it like that?" again.
Again, you may disagree that science can't answer "why" - but that kinda just proves my point that the answer depends on your philosophy and conceptions around what science can and cannot answer.
I address this in the last sentence of my previous post.
To reiterate, your argument does not matter because if you keep asking why, you are no longer answering the question that is being asked, but an entirely different question altogether. You can answer why there are so many metals. We might not figure out why the laws of physics are the way they are, but if you've gotten to that point where you're trying to answer that question, then you've deviated so far from the original question that you weren't even trying to respond to it to begin with.
Well, again, I don't agree that you can. I wouldn't call that an answer to "why". That's okay, we can disagree. That doesn't make my original answer wrong - just a different perspective.
"Why" is a valid question until and only until you get to the edge of knowledge. At that point it's "physical laws".
For example, "Why is the sky blue?" is a valid question and has answers.
"Even seemingly impossible questions like, "Why is there magnetism." can be answered by applying special relativity to electric fields. (Feynman answered this question poorly in the Horizon interview which might be where you got the idea that why is a bad question.)
You end up at, "Why are there photons?" which can't be answered. (Or maybe can't be answered yet.)
My interpretation of the question was why so many elements in the periodic table are metal and that does have an answer. It relates to the number of electrons on the outer shell that are mobile because the more electrons in an atom, the "farther" away they are and therefore are mobile. That electron mobility gives the element properties that we call "metal".
I don't disagree that that is a valid way to interpret the question. However, there were plenty of comments to answer that interpretation and I felt that an answer to the more fundamental interpretation could also be useful, for perspective.
I was just offering another viewpoint. Unfortunately that often results in downvotes. Oh well.